Testosterone propionate peak time

Testosterone, like many anabolic steroids, was classified as a controlled substance in 1991. Testosterone is administered parenterally in normal and delayed-release (depot) forms. In September 1995, the FDA approved testosterone transdermal patches (Androderm), and many transdermal forms and brands are now available including implants, gels, and topical solutions. A testosterone buccal system, Striant, was FDA-approved in July 2003; Striant is a mucoadhesive product that adheres to the buccal mucosa and provides a controlled and sustained release of testosterone. In May 2014, the FDA approved an intranasal gel formulation of testosterone (Natesto). A transdermal patch (Intrinsa) for hormone replacement in women is under investigation; the daily dosages used in women are much lower than for products used in males. The FDA refused approval for Intrinsa in 2004 stating that more data regarding safety, especially in relation to cardiovascular and breast health, were required.

The partition coefficient of the ester in question is important because is
effects how long the drug itself stays in the system. If the testosterone transfers
too quickly from the oil to the blood, the result is a sudden spike in testosterone
which then rapidly drops once the dose has been used up. In the example of free testosterone injected into
the muscle from a water suspension (as in Aquiviron, mentioned above), the testosterone
is essentially immediately available to the bloodstream due to its low partition
coefficient, and thus there is an immediate spike of testosterone which is used
up quickly in the body.

The second theory is similar and is known as "evolutionary neuroandrogenic (ENA) theory of male aggression". [77] [78] Testosterone and other androgens have evolved to masculinize a brain in order to be competitive even to the point of risking harm to the person and others. By doing so, individuals with masculinized brains as a result of pre-natal and adult life testosterone and androgens enhance their resource acquiring abilities in order to survive, attract and copulate with mates as much as possible. [77] The masculinization of the brain is not just mediated by testosterone levels at the adult stage, but also testosterone exposure in the womb as a fetus. Higher pre-natal testosterone indicated by a low digit ratio as well as adult testosterone levels increased risk of fouls or aggression among male players in a soccer game. [79] Studies have also found higher pre-natal testosterone or lower digit ratio to be correlated with higher aggression in males. [80] [81] [82] [83] [84]